The following remarks and most links are destined for physicists
or other well informed people with scientific interests. Only the first
link below is also interesting for aesthetical reasons and therefore no
experts only site.

For I'm myself a physicist, I want to put a few remarks first. The most
fundamental questions in physics nowadays are related with elementary particles
and the unification of all forces between these.

Since the 70's there has been absolutely no real theoretical
advance. At that time Salam and Weinberg derived the unification of electromagnetic
and weak interactions into one generalized force, which holds its uniqueness
at energies of around 100 MeV and more and distances of 10-18
m and less. Following this success were numerous attempts to unify this
interaction with the strong (nuclear related) force.

But these trials gained up to day no convincing results: besides the
theory is not unique by theoretical aspects, the most widespread versions
are already falsified by experiments, which showed no verifiable proton
decays, setting a lower limit for the half life time of this nucleon. And
so the simplest model symmetry SU(5) is along with a number of compelling
ones already excluded. It's simply not known, if these attempts will succeed
anyway in the way followed in the last decades.

Even worse is the situation with gravity: not only nobody knows now
really, how to unite it with the other interactions, we know on the other
side there are really intrinsic problems with it (General Relativity) and
the non-gravitational, but relativistic quantum field theories. For example
the effects for an infalling observer near the principal reachable singularity
at the center of black holes are beyond our proved theories and even more
the first 10-25 s and less pose great problems
for these theories, which work well at other conditions.

Finally we are waiting for any type of breakthrough, and I personally
doubt heavily, that the current trials heading in different directions
will deliver any usable results. What we lack, is a new idea. For
example, the open question of General Relativity, the cosmological constant,
raises further questions: what is it's value - and why has it the value
it has? The answer may come from a theory we not know until yet (Quantum
Field Theory delivers no acceptable value so far).

Not so far away we even not know with absolute certainty, if neutrinos
have a rest mass. This rest mass - now considered as probable - can have
big consequences for elementary particle Physics and also for Astronomy.

Here follow some links to mainly principal questions, but the first
is also to enjoy the beauty of a natural phenomenon.

The particle stream originating in our sun and general referred to
as solar wind interacts strongly with the magnetic field of the planets
of our solar system which feature such a field. Around one million tons
of particles are send into space in every second by our sun, and for example
the Voyager probes showed giant aurora phenomenons in the Jovian atmosphere.
In the same way as the charged particles, trapped in the magnetic field
of the planet, enter in high latitudes the atmosphere of Jupiter, they
do it on our planet and the others with a magnetic field.

From high latitudes on Earth the classical Aurora can be observed (of
course only in the so-called polar winter). It's the region where the field
converges and carries charged particles into the atmosphere, there inciting
luminous phenomenos in the upper part of it: the molecules (and atoms)
of the air take the energy from the incoming particles and enlight often
great parts of the (night) heaven.

These Auroras are feeble and the low brightness poses difficulties to
photograph them. Best viewed they are with the human eye, which can adapt
to a wide variety of illuminations. But this fine homepage offers nonetheless
a number of excellent pictures of the Aurora. Besides further links to
related sites there are explanations of the observed effects, predictions
of activities (especially interesting for people in high latitudes of course,
but it is true, that even at locations like Hawaii there can be seen -
eventually one time in a century - at rare oppurtunities some of them.

As a final remark, the solar activity plays a major role in the strength
of the Aurora and the now fast rising activity (maximum is expected for
1999 or 2000) will cause more and stronger Auroras than at the average.

A very comprehensive site with news, links to physical societies etc.,
which already won a number of awards. From there you should be able, to
get most interesting actual informations, for example also standard frameworks
from CODATA and others are listed.

The first one is more for generally particle physics interested people and
available in several languages,
while the second one is for experts, mainly an electronic journal for physicists working on these high energy topics --- also some astrophysical and cosmological topics are discussed. Both are good main sources for the
interested anyway.

He is a multiple decorated, leading specialist for Solar Astrophysics
and neutrinos. If you don't know the connection of the two, consider the
following.

The only star we can precisely scrutinize by physical standards so far
is our sun. Besides the direct measurement of electromagnetic waves, which
originate in the photosphere and above and deliver therefore no direct
hints
about the solar interior. Alternative with surface wide Doppler measurements
the helioseismology is performed, which allows similar as the earthquake
measurements by identifying acustic waves derivation of parameters of the
Sun even in central regions - better than simple flux measurements and
similar methods but it's also an indirect way.

The only method to get direct evidence of the nuclear fusion reactions
in the Suns core up to now is counting the neutrinos produced in these
reactions. But since decades we know, that there arise new problems.

First of all, the neutrinos are the least well scrutinized particles,
whose existence is proved, so far. Second, exact solar models require cross
section knowledges and plasma features in an environment, which can not
exactly reproduced in our laboratories.

The major problem now is a big discrepancy between the neutrinos, which
should be produced in the Sun according astrophysis and nuclear physics,
and the measured ones in different ranges of energy.

Astophysical it seems unlikely, that there are major faults in the calculations,
for the models describe well the properties of star clusters, where many
results of the models can be verified.

Probably the elusive neutrinos have to do with this difference. It seems
now, that they have a tiny rest mass and therefore are responsible by some
sort of change between different types of neutrinos.

But this complex has to be solved precisely in future - and you will
gain all relevant information at Bahcalls homepage.

Here the results of the leading solar neutrino experiment are presented,
which are conducted by an European colloboration. Besides other things,
you could download a 1.3 MByte postscript file which contains a good paper
about the neutrino complex for the interested. Despite being from 1997,
this is a good state description. Now the GALLEX experiment is transformed
into GNO, which is planned to increase from 30 to 100 tons of gallium content
and to run for at least one further decade. These pages are obviously now
under redesign and you should await the adaptation to the GNO successor.

This is a new type of neutrino observatory, which exploits the Cherenkov
radiation to detect all types of neutrinos, and not only electron
neutrinos like the chemical experiments at Homestake (Chlorine), GALLEX
or SAGE (Gallium). There are good prospects for a big leap in the theory
regarding the neutrino properties. In June 1999 the first two neutrinos
were already observed. Watch out for the measurements to come.

The possibly most ambitious neutrino experiment so far: it tries to
detect low energy neutrinos in real time (remember, that the chemical experiments
"only" sum up events for certain time spans). It relies on the neutrino
scattering by electrons and is therefore also sensitive for different neutrino
flavors. Full operational state should be achieved at the end of 1999.

These are the two Japanese neutrino detectors, which are no chemical
experiments but feature an even higer energy limit due to the utilized
reactions. Look regularly at this site, because these ongoing experiments
produce results faster than the long time chemical experiments. The two
are mostly named "Kamiokande" and "Super-Kamiokande".

This German site - presented almost entirely in English - is the internet
vehicle of the famous "Gesellschaft für Schwerionenforschung" in Darmstadt,
Germany. There are the most of the so-called transurane elements produced
by violent nuclear reactions of colliding heavy ion nuclei. For this purpose
and other studies like highly excited nuclear states and generation of
radiation as an - beside others - medical application.